1. Field of Invention
This invention presents an apparatus and method to mechanically orient perforating systems in a well relative to other devices, conduits, wave-guides, and electrical cable disposed in a well.
2. State of the Art
Typically to extract fluids from below the earth's surface, a casing is run into a penetration made in the earth, referred to herein as a well bore, and a length of casing is disposed concentrically inside the well bore. This casing is grouted into the well by placing a cement grout in the annular space between the casing outer surface and the well bore forming a bond between the casing's outer diameter and the well bore. Production tubing or drill pipe may also be deployed within the casing. Subsequently the casing (or tubing or pipe, if applicable), the cement, and at least one subterranean formation are penetrated by the use of a variety of perforating systems known to those familiar with oil and gas production, typically consisting of explosive charges disposed inside a tubular housing connected to a surface detonation device by an electrical conductor. The perforating systems when actuated form high-pressure exhaust jets and their resulting shock waves penetrate the casing (or tubing or pipe, if applicable), cement and subterranean formation. Other types of perforating systems utilize high pressure fluids and or abrasives to cut through the casing (or tubing or pipe, if applicable), the cement, and the formation to create the required perforation or slot, and thereby allow communication of subterranean fluids into the casing, pipe, or tubing being perforated. In any case (the explosive charge method, or the hydraulic penetration or other penetration methods), the objective is to allow for a pressure or hydraulic communication path to be formed from the inner diameter of the casing, pipe, or tubing into the subterranean formation and each is collectively referred to herein as a perforating gun.
In certain cases, the casing, pipe, or tubing to be penetrated is positioned in the well adjacent other devices or conduits which may be disposed parallel to the outer diameter of the casing, pipe, or tubing at the depth to be penetrated. When perforating the casing, pipe, or tubing in these situations, the resulting penetration operation may also inadvertently penetrate or otherwise damage the adjacent device or conduit. Hence, in the situation involving any parallel conduits or devices disposed in well at the depth where the penetration is to be made as in some dual string completion systems, or when other devices are located outside the casing, pipe, or tubing to be perforated at the same depth, it is possible to inadvertently penetrate these other conduits or devices. These devices and conduits can be control lines, dual production tubing, casing strings, pressure gauge carriers, geophones, hydrophones, wave guides, sensing devices, and many other tools and instruments disposed in subterranean environments.
The device and method described herein aligns the perforating systems such that, when they are energized, they penetrate a predetermined radial direction relative to this inventions apparatus, and by fixing other devices and conduits in a position that is known relative to the apparatus of this invention a method is presented to avoid damaging or penetrating devices and conduits upon perforation. An orientation method and apparatus disclosed also accomodates perforating systems to purposely penetrate, ignite, or excite devices and apparatus connected to the casing or tubing in which the perforating system is disposed concentrically inside, such that the device, explosive charge, or conduit connected to the pipe is disposed in a known radial position relative to this inventions orientation device.